1. Field
One or more embodiments relate to a biosignal amplifying circuit, and more particularly, to a biosignal amplifying circuit which can amplify and filter a biosignal measured from a user via an electrode in a biosignal measurement apparatus measuring the biosignal from the user via the predetermined electrode.
2. Description of the Related Art
As used in the embodiment, the term “Ubiquitous” means an information communication environment where a user can be free to access networks at any place without being conscious of the surrounding networks or computers. If ubiquitous is commercialized, anyone can readily use information technology not only at home or in a car, but also even on a mountaintop. Also, the commercialization of Ubiquitous may expand the information technology industry or the scope corresponding thereto by increasing the number of computer users who are connected to networks. Because of its advantage that users can access networks without restriction to time and place, not to mention its portability and convenience, countries worldwide are expanding development and competing in Ubiquitous-related technology now.
Ubiquitous-related technology may be applied to any field in human life. Particularly, a Ubiquitous-Health Care (hereinafter, U-HealthCare) has recently been in the spotlight as a remarkable technology field owing to a recent health craze and “well-being” phenomenon among people. U-Health Care refers to a ubiquitous technology in which chips or sensors associated with a medical service are installed at various living spaces of the human being so that all the people can be naturally provided with medical services anytime and anywhere. According to such a U-Health Care, health care in hospitals including various kinds of health diagnoses, disease management, emergency management, consultation with a doctor, etc., can be naturally implemented in each person's daily life without having to actually visit the hospital.
For example, a diabetic may wear a belt having a blood-sugar management program for blood-sugar management. A blood-sugar sensor attached to the belt may check the blood-sugar of the diabetic upon a specified occasion, and calculate the amount of required insulin corresponding thereto. When the blood-sugar of the diabetic becomes drastically low or high, the belt may provide the blood-sugar information to his/her attending physician via a wireless network, and the attending physician who has received the blood-sugar information may write out an optimal prescription or take the optimal action for the medical emergency.
As an example of U-HealthCare, a portable electrocardiogram measurement device is currently commercialized, and is used for users suffering from cardiac diseases. A portable electrocardiogram measurement device, which may be portable, may constantly measure an electrocardiogram, and cope with sudden cardiac diseases considering a characteristic of cardiac diseases that may be suffered from anytime and anywhere, may correspond to a device showing a significant advantage of U-HealthCare.
An electrocardiogram measurement device corresponds to an apparatus for obtaining an electrocardiogram waveform for sensing a weak electrocardiogram generated in a body, and determining whether a cardiac disease exists. Accordingly, elements such as a structure of an electrode, a shape, a material, and the like for sensing a weak electrocardiogram signal, which is generated in a body, have a significant effect on performance and utility of an entire measurement system, in a portable electrocardiogram measurement device.
An electrocardiogram is measured via a plurality of electrodes considering a characteristic of the electrocardiogram. Specifically, an electrocardiogram of a user may be measured via at least two electrodes. According to a related art, after an electrocardiogram signal measured from a user via the at least two electrodes is inputted through a buffer connected with each electrode, the electrocardiogram signal is amplified by an amplifier, and is filtered using a high pass filter (HPF).
Next, the signal, amplified and filtered using the HPF, is processed via a predetermined signal processing module, and the signal processing module may measure and interpret the electrocardiogram of the user. Accordingly, a process of amplifying an electrocardiogram signal measured via an electrode, and filtering the electrocardiogram signal using an HPF is a flow generally required to perform when the electrocardiogram signal is measured. The above flow is generally applicable to all biosignal measurements besides an electrocardiogram signal.
A biosignal measurement apparatus according to a related art includes at least two buffers, an amplifier, and an HPF as a configuration of a biosignal amplifying module for amplifying a biosignal measured via an electrode and filtering the biosignal using an HPF. Specifically, when each biosignal is inputted through at least two buffers connected with at least two electrodes, the biosignal is amplified by the amplifier. Next, a predetermined process is performed based on a signal filtered using the HPF.
The configuration is complicated since it is required that a biosignal measurement apparatus according to a related art should include a plurality of multistage operational amplifiers in order to respectively include the at least two buffers, the amplifier, and the HPF as a configuration of a biosignal amplifying circuit. Therefore, the biosignal measurement apparatus according to the related art has a drawback of being unfavorable for miniaturization.
Also, since an amplifier according to a related art includes a predetermined active element chip, a configuration of a biosignal amplifying circuit becomes more complex and larger. Accordingly, there is a problem that an amplifier according to a related art is unfavorable for a portable biosignal measurement apparatus enabling miniaturization and slimming.
Therefore, a biosignal amplifying device, which can simplify a biosignal amplifying circuit amplifying and filtering a biosignal measured from a user via an electrode in a biosignal measurement apparatus more significantly, and enable miniaturization, slimming, and minimization of production costs, is required.